This feud is getting nasty!

Kim Kardashian, 35, slammed frenemy Taylor Swift, 26, in her latest interview with GQ, in which she remained adamant that the pop star knew Kim's husband, Kanye West, 39, would take aim at her in his song "Famous."

Now In Touch can exclusively reveal the TRUTH behind that infamous lyric, "I feel like me and Taylor might still have sex. Why? I made that bitch famous" — which Tay's camp swore she did not grant Yeezy permission to sing.

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A source exclusively reveals that Kim "is sick of everyone thinking that Taylor is holier-than-thou" after the two musicians discussed the lyric at length.

"Taylor spent the whole conversation with Kanye kissing his ass, telling him what a genius he is," the insider adds. "The more she keeps coming after him, the more it looks like she has something to hide."

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Taylor has already taken legal action — and, to no one's surprise — plans on writing harsh lyrics about the reality star.

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Don't expect Kanye to sit this one out, either. The source notes "he's planning an epic takedown on his upcoming tour."

"It's going to be absolutely merciless."

For more on this story, pick up the latest issue of In Touch, on newsstands now!

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